I own a 1983 Dyna fxrs with a shovelhead motor. I am running a set of 1 3/4" drag pipes. I can not stop blowing the front gasket out. Is there anything I can do to help this? Or does anyone know if a 2 to 1 pipe assembly would be better? I am tired of supporting the gasket companies.
Thanks for any help!!!
athome01

 

I am not sure if this is your problem but from past experiences this is usually due to improperalignment of the pipe flange to theexhaust port.Ifthe pipe does not fit tight againstthe port all around (try connecting it without a gasket to see) you may have issues blowing out the gasket. You could try adjusting your mounting brackets, but it may end making the overall fitof the pipe out of alignment on the bike. I have tried using 2 gaskets and this has worked in some cases. Make sure the gaskets you get have the copper ring on them as well. Note the picture of my 72 below. As you can see there is some difference in the fit front to back on the front pipe, but it is not enough to cause gasket failures. The slight mis allignment on my 72 is due to the additional height of the stroker kit.

 

Way back in the Shovel Head days we foundand used a 'Copper Crush Gasket' for theproblematic sealing problems of the pipes. It just so happened this crush gasket wasa stock itemona 450 Hondaexhaust system....it fit like a glove and itworked in the most trouble some builds. I don't know if they are still available or not but it's worth a shot.

 

They still make the copper crush gaskets and they work great, be sure not to over tighten the single bolt on the cylinder head, people have a tendancy to strip them out.

 

The exhaust you have may not be square to the head exh ports or exh ports on heads are worn from previous loose exhaust.Start first by holding exh up to ports with nothing else installed.How well can you make the flanges sit?You may have to adjust pipes elsewhere if a good seal is found this way.Dont be afraid to use more than one exh gasket if needed even using hi temp sealant if need be. Shovelhead exh pipe bolts love to pull treads in the heads-how are they?You are better off using a stud rather than a bolt for these.Double jam nuts usually work the best.Sure the exhaust you have may not sit true on anyones shovel but the above has worked,if not you may want to contact the pipe builder.

 

What I used to do on Shovels is to put a stud into the head instead of using just a bolt. You can get more torque on it this way. Also use the copper gaskets.